Nowadays, more and more videos have been transmitted through a network. Sometimes people may need to quickly browse a network video to know the contents of the video. A video includes image frames, among which keyframes can be extracted and reproduced on a screen at a proper rate, so as to realize video browsing. During the process of extracting keyframes, a terminal segments the video into at least two shots. A group of keyframes are selected for each shot in response to changes of image quality and video contents according to boundaries of the shot.